My Redmaids - Redmaids’ High School (redmaidshigh.co.uk)
(Note this will work with either Internet Explorer or Chrome not Firefox or Safari)
Open/Run the file:
Install the certificate (replace 'bloxx' with 'Netsweeper Root CA' in all further images)
Select the 'Place all certificates in the following store' and then click 'Browse...'
Choose 'Trusted Root Certification Authorities' then 'OK'.
Next
Now 'Finish'
...and close internet explorer or chrome, reopen and start using the internet.